Height Adjuster for Glass Assembly

ABSTRACT

A plug assembly including: a housing; glass assembly including a plug; a height adjuster including a mechanical adjuster; wherein: the glass assembly and the height adjuster are arranged in the housing; and the height adjuster is arranged to apply pressure to the glass assembly; and the height of the mechanical adjuster is adjustable.

FIELD OF INVENTION

The present application is a Continuation in Part of, and claims priority to, U.S. application Ser. No. 17/480,805 filed Sep. 21, 2021; hereby incorporated by reference.

FIELD OF INVENTION

The present invention relates to a plug assembly for the temporary blocking of fluid flow through a downhole tubular. More specifically it relates to a height adjuster for adjusting the size of the opening into which the glass assembly is installed.

BACKGROUND

During the drilling, testing, completion, fracking, production and abandonment stages of hydrocarbon wells there are many uses for plugs assemblies that create a fluid barrier in the well. Some of these uses are not permanent such as plug and abandonment, but rather temporary, where it is desired to re-establish fluid flow at a later stage. Some examples of such temporary uses of plugs are for flotation, well testing during completion, packer setting and fluid loss devices. Temporary plugs may thus be installed in any kind of piping installed downhole, for example casing, liner, or other tubing. The only difference between these is the inner diameter of the pipe.

When flow through the well is to be established, the plug is broken. This preferably done without spearing, milling, or other mechanical intervention from the surface. Ways to achieve the desired breaking is through the use of pressure, pressure pulses, or explosives. When the plug is removed it allows for a nonrestricted fluid flow past the opened plug assembly, and for many applications after opening of the plug assembly this is required in order to pass various tools past the plug assembly. Plugs can be made of various materials, such as metal, stone, or composites, or more frangible materials such as glass or ceramics. Frangible materials are often preferred as they have the advantage of being relatively insensitive to pressure, temperature and chemical corrosion, yet by their frangible nature they are relatively easy to destroy when used as the fluid blocking part of plug assemblies. Particularly glass, e.g. hardened glass, can be made to break into very small pieces that will not pose a problem in most wells. Frangible materials are therefore well suited for opening the plug assembly by constructing the plug assembly with a breaker of small amounts of explosives that will crush or shatter a glass disc, and open the plug assembly, but not damage the production tubing or casing the plug assembly is installed in. The breaker will then make contact with the plug on a relatively small area. Frangible materials will typically shatter, and this property of breaking under a large point pressure load is taken advantage of by employing a breaker object with a relatively small impact area, such as a thin edge like a knife blade, a point such as a pin, or even a small ball.

A problem with many frangible materials is that they can prematurely break where they contact a hard surface such as a metal surface. This can happen when the plug is being installed or even when changes in pressure in the well causes minute movements of the glass assembly. One way to overcome this issue is to put a bearing ring of a soft material (e.g. plastics such as polyether ether ketone; PEEK) between the frangible plug and any hard surface (e.g. steel) it abuts. This allows the force on the plug to be transferred to the bearing ring instead. The bearing ring will then compress and prevent the plug from coming in contact with a hard surface. The plug should be installed in such a way that it is well secured and will not break easily from fluctuating well pressures (i.e. from direct pressure rather than from a breaker). The plug should also be secured in such a way that it forms a fluid tight seal as the specifications of the specific application require until it is removed. Leakage of fluid between the plug tubular and the surrounding area, such as the annulus, should be prevented as far as possible.

Loose parts in the wellbore can cause a lot of damage to equipment and even obstruct the well bore. Thus, the plug should preferably break into fragments small enough to not be a potential problem in the well. The various other parts of the plug assembly should preferably be prevented from entering the wellbore when breaking the plug, so they or pieces thereof will not be a potential problem in the well. These other parts should also preferably be prevented from moving once the plug assembly is opened. There should not be a possibility of a partial opening of the plug, i.e. the system should preferably only allow for the plug to be fully intact or fully broken, not partially broken. If partially broken, it would not be possible to open fully with pressure from above since a partially open plug assembly could not be pressurized, so different means to open it fully would have to be used.

The inner diameter of the tubing the plug assembly is installed in should preferably be fully restored upon opening of the plug assembly, i.e. the plug assembly should not have a smaller inner diameter than the inner diameter below and above the plug assembly. This allows for a nonrestricted fluid flow past the opened plug assembly, as well as unrestricted passing of tools up to the inner diameter of the pipe the plug sits in.

Advantages of the Present Invention

It is an object of the present invention to provide a plug assembly comprising a plug that can hold pressure while being used for its purpose, and then be safely and completely opened after it has served its purpose. Once open, the plug assembly parts should stay in place, and said parts or pieces thereof should not enter the wellbore.

It is an object of the present invention to provide a plug assembly comprising a plug that has an improved sealing of said plug before it is opened. Another object of the present invention is to provide a plug that is less likely to be prematurely broken during assembly, insertion into the well, or by movement of the plug tubular in the pipe (e.g. from movement or pressure changes in the pipe or formation). This is achieved by the geometries of the plug and/or stabilizer and/or glass assembly. By the plug not having sharp corners, but rather rounded edges, it is less likely for said rounded edges to be chipped off during assembly, or when the plug experience relative movement against the surrounding components, such as when the plug is inserted into the well, or the plug housing shifts with the formation, or when the pressure applied from up hole or downhole or the formation changes.

Usually there is no bearing ring or stabilizer between a plug surface parallel with the plug housing and said housing or sleeve or whatever component the plug is to seal against. By adding the stabilizer, it helps stabilizing and centralizing the plug in place. If made of a softer material, similar to the materials the bearing rings are made of, it also helps cushion the side of the plug against any sideways impacts, and gives it a little extra play for movement. Rig operators are often concerned that u plugs are exposed to impacts and vibrations both during transport and operation, and therefore it is usually required that the plug assembly must be able to withstand shock and vibrations. Adding a stabilizer helps fill this requirement.

Not being bound to a specific theory, possible reasons for the improved sealing of the seals when on a surface not parallel to the plug housing but rather sloped is that the seals will receive less force than when on a surface parallel to the plug housing, such as at a parallel side of the plug. Such nonparallel surfaces may be better supported by the plug and housing. Thus, the seals may experience less force trying to push them out of the way. The seals would also have to move further, so it would take more force, to move them when on the sloped walls than when on a parallel, straight up and down wall. The pressure on the seals results in less of a risk of extrusion of said seals (e.g. O-rings), as the gap will be closed by the forces applied by the pressure. This may then lead to the seals being able to take higher pressure and leak less. This effect would be especially advantageous when the seals are also pressed up against the stabilizer, in which case this holds them well in place. Thus, this allows for better force distribution and reduced deformation of both seals and bearing rings under different pressures and temperatures to increase protection of the plug and form a better seal. The combination of the seals and the stabilizer provide an improved effect for both as they can help hold each other in place. When the various parts for the glass assembly are made, they will of course be made to specifications, but there will usually be some variation in their manufacturing tolerances. This can cause assembly to be difficult, and the final seal to be not optimal. For example, if the components of the glass assembly are made slightly larger than specified, the seal will be very tight and the assembly hard to get into place. Likewise, if too small, the seal achieved may not have quite enough pressure on it from the components and may leak. The height adjustor addresses these problems. By loosening it, insertion of the glass assembly into its place in the housing is easy. When the glass assembly is put in place, the height adjustor can be adjusted so it applies just the right amount of pressure on the glass assembly, not too much pressure which could ultimately crack the plug or damage other components, and not too little pressure so the seal would be too loose and could leak, but just right to form a proper seal

Short Summary of the Invention

In some aspects, the techniques described herein relate to a plug assembly including: a housing; glass assembly including a plug; a height adjuster including a mechanical adjuster; wherein: the glass assembly and the height adjuster are arranged in the housing; and the height adjuster is arranged to apply pressure to the glass assembly; and the height of the mechanical adjuster is adjustable.

In some aspects, the techniques described herein relate to a plug assembly, wherein the height adjuster is restorative.

In some aspects, the techniques described herein relate to a plug assembly, wherein the height adjuster is non-restorative.

In some aspects, the techniques described herein relate to a plug assembly, wherein the height adjuster further includes an adjustment seat, and the adjustment seat is in contact with the glass assembly

In some aspects, the techniques described herein relate to a plug assembly, wherein the plug assembly further includes as seat, wherein the seat supports the glass assembly from one side and the height adjuster supports the glass assembly from the other side.

In some aspects, the techniques described herein relate to a plug assembly, wherein the mechanical adjuster is arranged to change the pressure applied to the glass assembly.

In some aspects, the techniques described herein relate to a plug assembly, wherein the mechanical adjuster is a spring.

In some aspects, the techniques described herein relate to a plug assembly, wherein the mechanical adjuster is threaded.

In some aspects, the techniques described herein relate to a plug assembly, wherein the glass assembly further includes a bearing ring arranged between the plug and the height adjuster.

In some aspects, the techniques described herein relate to a plug assembly, wherein the height adjuster is configured with a first and second position; wherein: in the first position of the height adjuster, the height adjuster applies a first pressure to the glass assembly; and in the second position of the height adjuster, the height adjuster applies a second pressure to the glass assembly.

In some aspects, the techniques described herein relate to a plug assembly 10, wherein in the first position, the height adjuster applies no pressure to the glass assembly.

In some aspects, the techniques described herein relate to a plug assembly, wherein the height adjuster holds the glass assembly in place, while the plug is intact and stationary.

In some aspects, the techniques described herein relate to a plug assembly, further including a breaker object wherein: in the first position, the plug is intact and stationary; and in the second position the breaker object has made contact with the plug.

In some aspects, the techniques described herein relate to a plug assembly 13, further including a shear ring which supports the seat, wherein: the breaker object is not in contact with the plug in the first position; the shear ring has sheared the shear ring is arranged to shear when a pressure above a threshold pressure is applied to the glass assembly, releasing the plug and moving to the second position.

In some aspects, the techniques described herein relate to a plug assembly 14, wherein the glass assembly further includes a first bearing ring between the height adjuster and the plug, wherein the first bearing is not in contact with the plug when in the plug assembly is in the second position.

In some aspects, the techniques described herein relate to a plug assembly, wherein the glass assembly further includes a stabilizer and wherein: the stabilizer is at least partially non-elastomeric; the plug further includes a middle edge surface which contains the widest portion of the plug; and the stabilizer is arranged around at least a portion of the middle edge surface.

In some aspects, the techniques described herein relate to a Method of installation of glass assembly into a plug assembly, the plug assembly including: a seat; a glass assembly including a plug; a height adjuster arranged with an adjustable height; wherein the seat is arranged to support the plug; a gap is arranged between the height adjuster and the seat the method including the steps of: (a) adjusting the size of the gap to be larger than the thickness of the glass assembly with the height adjuster; (b) inserting the glass assembly into the gap; (c) resting the glass assembly on the seat; (d) adjusting the size of the gap to be smaller than in step (a) with the height adjuster.

In some aspects, the techniques described herein relate to a method 17, wherein in step (b), the glass assembly is in contact with the height adjuster.

In some aspects, the techniques described herein relate to a method, wherein in step (c), the glass assembly is not in contact with the height adjuster.

BRIEF DESCRIPTION OF THE FIGURES

The above and further features of the invention are a set forth with particularity in the appended claims and advantages thereof will become clearer from consideration of the following detailed description. Embodiments of the present invention will now be described, by way of example only, with reference to the following diagrams wherein:

FIG. 1A discloses a side view of a longitudinal cross section of a first example of a plug tubular

FIG. 1B discloses a close up of the glass assembly of FIG. 1A

FIG. 1C discloses a perspective cross-section view of a second example of a plug tubular

FIG. 1D discloses a side view of a longitudinal cross section of a third example of a plug tubular

FIG. 2A shows a side cross-section of an example of a glass assembly without curved surfaces

FIG. 2B shows an exploded view of an example of a glass assembly without curved surfaces

FIG. 2C discloses a perspective cross-section of an example of a glass assembly

FIG. 2D discloses an exploded view of the example of FIG. 2C

FIG. 2E discloses a perspective cross-section of an example of a glass assembly with multiple plugs

FIG. 3A discloses a side view of a longitudinal cross-section of the operation of a plug tubular in the first position

FIG. 3B discloses a side view of a longitudinal cross-section of the operation of a plug tubular in the transition between the first and second positions

FIG. 3C discloses a side view of a longitudinal cross-section of the operation of a plug tubular in the second position

FIG. 3D discloses a side view of a longitudinal cross-section of the operation of a plug tubular in the third position

FIG. 4 discloses a side view of a longitudinal cross section of an example of a glass assembly with a height adjuster

FIGS. 5A-5C shows a cross-sectional side view of examples of plug surface geometries without curved surfaces

FIGS. 5D and 5E disclose a cross-sectional side view of examples of plug surface geometries with curved surfaces

FIG. 6A discloses a side view of a longitudinal cross section of an example of a plug tubular with a plug assembly in the first position

FIG. 6B discloses a closeup of the plug tubular example of FIG. 6A

FIGS. 6C-6F discloses the plug tubular example of FIG. 6A as the plug assembly moves from the first position to the second position

FIG. 7 discloses another example of a plug assembly

FIGS. 8A and 8B disclose an example of a height adjuster as the plug assembly in the first and second positions

FIG. 9 discloses an 3D exploded view of an example of a plug assembly

REFERENCE NUMBERS AND CORRESPONDING ELEMENTS

-   10 Plug 10 -   11 Sealing Element 11 -   12 Stabilizer 12 -   13 Sealing Area 13 -   14 Bearing Ring 14 -   15 Glass Assembly 15 -   16 Sealing Bearing Ring 16 -   17 Sealing Bearing Ring Edge Groove 17 -   60 Plug Surface 60 -   61 Top Surface 61 -   62 Bottom Surface 62 -   63 Top Edge Surface 63 -   64 Middle Edge Surface 64 -   65 Bottom Edge Surface 65 -   66 Edge Surface -   20 Seat 20 -   21 Seat Surface 21 -   22 Breaker Pocket 22 -   23 Seat Lip 23 -   24 Seat Pocket 24 -   30 Breaker Object 30 -   31 Breaker Holder 31 -   32 Breaker Assembly 32 -   40 Height Adjuster 40 -   41 Adjustable Seat 41 -   42 Mechanical Adjuster 42 -   50 Shear Ring 50 -   51 Shear Ring Lip 51 -   52 Shear Ring Body 52 -   100 Plug Tubular 100 -   110 Upper Tubular 110 -   120 Lower Tubular 120 -   130 Tubular Body 130 -   140 Housing 140 -   200 Plug Assembly 200

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying figures. Alternative embodiments will also be presented. The figures are intended to be read in conjunction with both the summary, the detailed description, and any preferred and/or particular embodiments, specifically discussed or otherwise disclosed. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided by way of illustration only. Several further embodiments, or combinations of the presented embodiments, will be within the scope of one skilled in the art.

As described, there are various ways to open plugs. In the examples given below, the plugs are opened applying pressure, which brings a breaker object 30 into contact with the plug 10, causing it to break. The breaker object 30 does not have to be operated in this manner. Instead applied pressure or a different kind of signal such as that provided by a control line could cause the breaker object 30 to be brought into contact with the plug 10, or it could cause the breaker object 30 to explode, and this explosion could break the plug 10. In some cases the seat 20 will not necessarily move in an axial direction, or move at all. Alternatively, the plug 10 may be designed to be broken by milling it open. The plug 10 could then be arranged in a glass assembly 15, and said glass assembly 15 could be directly secured in the housing 140.

Plugs that can be opened using pressure, operate upon the principle of a plug 10 arranged in a housing 140 of a plug tubular 100. The plug 10 is part of a glass assembly 15 which prevents fluid connection between the upper tubular 110 on the upstream side of the plug and the lower tubular 120 on the downstream side of the plug. A glass assembly 15 comprises the plug 10 and is arranged on a seat 20 for support. Pressure is applied to one side of the plug (normally from the upstream side). At a predetermined absolute pressure, or a predetermined differential pressure, the seat 20 moves in an axial manner until the plug 10 makes contact with a breaker object 30. Upon contact, the plug will disintegrate, and flow through the tubular 100 is restored. The sealing area 13 is the area or areas where it is fluid tight between the plug 10 and the tubular body 130 and/or the plug 10 and the seat 20. Please note that although the examples below refer to a plug 10 opened by applying pressure from above, e.g. a so-called pump open type plug, it is also possible to open the plug 10 with by applying pressure from below (or reducing pressure above), e.g. a so-called surge open type plug. Also note that the plug assembly 200 can be used in a casing, a liner, a tubing, or any other metal pipes used downhole, with any outer and inner diameters.

One important feature for this invention is the curved outermost edge of the plug 10 and details of the sloped or perpendicular sealing area 13.

FIGS. 1A-1C disclose examples of a glass assembly 15 with a plug 10 in a plug tubular 100. The plug 10 prevents fluid connection between the fluid inside the upper tubular 110 on the upstream side of the plug and the fluid on the downstream side of the plug inside the lower tubular 120. The glass assembly 15 is arranged on a seat 20. At a predetermined absolute pressure, or differential pressure, the seat 20 moves in an axial manner until the plug 10 contacts a breaker object 30. Upon contact with the breaker object 30 the plug will break and flow through the tubular 100 is restored.

The plug tubular 100 comprises a plug assembly 200 arranged in a housing 140 in a tubular body 130. The tubular body 130 comprises an upper tubular 110 on the upstream side of the plug 10 and a lower tubular 120 on the downstream side of the plug 10. The plug assembly 200 comprises a glass assembly 15, a seat 20, a breaker assembly 32, and a shear ring 50.

The glass assembly 15 comprises a plug 10, a sealing element 11, a stabilizer 12 and a bearing ring 14. The sealing element 11 prevents fluid from traveling around the plug 10. In the example shown, this is found between the plug 10 and the housing 140 on one side and the plug 10 and the seat 20 on the other side. A bearing ring 14 is arranged between the plug 10 and the housing 140 one side and the plug 10 and the seat 20 on the other side. A common example of a sealing element 11 is an O-ring. Note that while glass assembly 15 is called a “glass assembly” it refers to the plug 10 (regardless of material, including non-glass materials).

The sealing area 13 is the area on the housing 140 and seat 20 that is in contact with the sealing element 11. It is this area which accounts for the plug 10 being fluid tight. The sealing element 11 could be arranged on the outside of the plug 10, in a groove in the plug 10, or a groove in the housing 140 and/or seat 20. As will be disclosed below, it is also possible for other elements to be fluid tight as well. Those elements will further contribute to the sealing area 13, but the often the main seal is formed by the sealing element 11. The sealing area 13 does not include the areas in which a fluid tight seal is not provided.

The stabilizer 12 helps to hold the plug 10 in place during operation. Depending upon the exact configuration, it may be possible for the plug 10 to twist in the housing 140 without it. Also, similar to the bearing ring 14 (discussed shortly) it can keep the edge of the plug 10 from making contact with any hard metal surface. The stabilizer 12 shown in all of the figures is curved to match the curved shape of the middle surface of the plug 10. The stabilizer 12 could also be called a middle bearing ring due to its position in between the two “outer” bearing rings 14.

While it is possible for the bearing rings 14 and/or stabilizer 12 to seal somewhat against fluid, and thus be included in the sealing area 13, it is preferable that the stabilizer 12 is not fluid tight. For installation, by cutting slits or separations in the stabilizer 12, it will make it easier (or perhaps even possible depending on the exact geometries) to install. If the stabilizer 12 is such a cut ring, the two ends of the cut can be made to overlap to make the diameter of the stabilizer 12 smaller so that it can be easily inserted. Depending upon the material and/or geometries, this may be necessary. Slits will render the stabilizer 12 non-fluid tight and completely ineffective as a sealing component. Additionally, another reason for not requiring that it be fluid tight is that a wider choice of materials is then available.

The main purpose of the bearing ring 14 is to help reduce the possibility of contact between the plug 10 and hard metal surfaces (e.g. the housing 140 and the seat 20). At higher pressures, a contact between a hard metal surface and the plug 10 could result in a premature breaking. Common materials for bearing rings 14 are soft enough to provide cushioning between the plug 10 and adjacent hard components, such as the seat 20 or housing 140, thus preventing premature breaking of the plug. An example of such materials are soft metals, rubber or plastics, preferably PEEK. Materials for a stabilizer 12 also include the same soft materials as are used for bearing rings 14, but hard materials such as those used for the other plug assembly components may be used, such as steel or glass.

If needed, the sealing element 11 can be held in place by a stabilizer 12 and/or a bearing ring 14. A stabilizer 12 prevents the sealing element 11 from being pressed toward the outside of the plug 10, and a bearing ring 14 can help hold the sealing element 11 from being pressed toward the inside of the plug when under operation. A breaker assembly 32 is an element that contains and supports the breaker object 30. A breaker object 30 is arranged to break the plug 10 when they make contact. In the example shown, the breaker object 30 is held in a breaker holder 31. It is also possible for the breaker object 30 to be directly affixed to the housing 140.

The glass assembly 15 is supported by the seat 20. The plug 10 will be directly or indirectly supported by the topmost portion of the seat 20, the seat surface 21. When the seat 20 moves in an axial direction, the plug 10 will move with it. In the example shown, the seat 20 has a breaker pocket 22 that is arranged such that the breaker object 30 pass through the seat 20. The seat 20 has a seat lip 23. This is a protrusion that extends past the shear ring lip 51 of the shear ring 50. Because the seat 20 extends at least a portion past the edge of the shear ring lip 51, the shear ring lip 51 is held in place when plug assembly 200 has completed its operation. Beneath the seat 20 is the seat pocket 24. The seat pocket 24 is a space that can receive the seat 20 when it moves in an axial direction under operation.

A shear ring 50 is arranged such that it supports the seat 20 on its shear ring lip 51. When the proper threshold pressure (absolute or differential) is reached, the shear ring will break into two different pieces. One portion will remain stationary, and the shear ring lip 51 will travel axially. Note that instead of a shear ring, shear pins, or other such elements could be used. Note that the shear ring 50 can have different shapes. That of FIGS. 1A and 1B have the shear ring lip 51 a distance from the edge of the shear ring 50 (this is sometimes referred to as a “T” shape), while that of FIG. 1C has the shear ring lip 51 on the edge of the shear ring 50 (sometimes referred to as an “L” shape). The purpose of the shear ring 50 is to shear into two pieces, the exact arrangement can be as required for a given application. By changing the thickness of the shear ring lip 51 or making it discontinuous around the edge of the shear ring 50, it can be easily adjusted to shear at different applied pressures. The shear ring lip 51 can then preferably be changed in thickness in the downward direction in the figures, as this protrudes into the hollow space of the receiving pocket 24 and no other components will have to be changed. It is also possible to make the shear ring 50 from different materials with different mechanical properties, and hence change the shear value.

Depending upon operating conditions and material composition concerns, it may be possible for the glass assembly 15 to include a plug 10 and a single sealing element 11, or a plug 10 and a stabilizer 12.

FIG. 1D discloses another example of a glass assembly 15 with rounded edges. The plug 10 in this example is different from the previous one. Rather than the rounded portion being in between two chamfered angled portions, the rounded portion is between a flat horizontal portion on the figure and an angled bottom portion. The glass assembly 15 comprises a plug 10, a sealing element 11 between the plug 10 and housing 140 and another sealing element 11 between the plug 10 and seat surface 21, a bearing ring 14 between the plug 10 and the housing 140 and a bearing ring 14 between the plug 10 and the seat surface 21, and a stabilizer 12 between the plug 10 and the housing 140 and/or seat surface 21.

It is possible that the stabilizer 12 is made up of more than one separate piece. For example, this could be due to the physical dimensions of the system or the shape of the plug 10 or housing 140 or seat 20. It could also make installation simpler. As shown in the previous figures, the bearing ring 14 and the stabilizer 12 help to hold each of the sealing elements 11 in place.

Also shown is the arrangement where the seat lip 23 is held in place by the shear ring lip 51 to prevent the shear ring lip 51 from entering the wellbore.

The preferred angle of the chamfers is between 1 and 45 degrees, preferably 25 to 45 degrees, measured from the centerline. 90 degrees (perpendicular to the centerline) is also a good alternative. The radius of curvature of the rounded outer edge is preferably between 1 mm and 10 mm. The angle on the overside and underside of the plug does not need to be the same.

While the tubular body 130 in the figures is shown as comprising an upper tubular 110 and a lower tubular 120, it could also be made of a single continuous piece.

In FIG. 1D, the rounded portion of the plug is between the top surface and the edge surface, as opposed to that of the middle. This is where the widest part of the plug 10 meets a surface with a different angle. Further details of the surface geometry will be discussed in FIGS. 5A-5E.

FIGS. 2A and 2B shows glass assemblies without curved surfaces. The top and bottom edge surface of the plug 10 is chamfered. On these chamfers is arranged a bearing ring 14. The sealing element 11 is arranged at the middle portion of the plug 10, which is straight. There is no stabilizer 12 or rounded middle edge surface as given in FIGS. 2C and 2D. In FIG. 2D, the stabilizer 12 is shown with a split in order to facilitate easier installation.

FIGS. 2C and 2D disclose an example of a glass assembly 15 with a curved edge surface. The plug 10 has a chamfer/bevel on the top and bottom edge surfaces with a rounded portion connecting them. On these top and bottom edges is arranged a bearing ring 14. As stabilizer 12 is arranged in contact with the rounded portion of the plug 10. Sealing elements 11 are arranged between each bearing ring 14 and stabilizer 12.

The plugs 10 shown in FIG. 2A and FIG. 2B plug 10 has some combination of vertical, chamfered, or beveled edges. In particular, the widest portion of the plug 10 has a vertical edge. However, where two straight edges meet (e.g. a corner or a chamfer), that point is vulnerable to stress. Especially the area between the widest part of the plug and the first surface with a different planar angle has a higher chance of breaking. Please note that the plugs 10 of the examples of FIGS. 2A and 2B are the same, but the glass assemblies 15 differ in that while there is only one sealing element 11 in FIG. 2A, there are two sealing elements 11 shown in FIG. 2B. If the righthand sealing element 11 of FIG. 2B were removed, this figure would depict an exploded view of FIG. 2A.

Under higher pressures, these areas can become susceptible to premature breakage. However, the plug 10 in FIG. 2C and FIG. 2D as shown has a chamfered edge on the top and bottom and a rounded edge between them. This gives the outermost edge of the plug 10 a curved profile. This curved profile allows the plug 10 to be more robust against unwanted breakage than a sharp corner would be.

FIG. 2E discloses an example of a glass assembly 15 made of multiple layers. This can either be multiple layers of material in the same plug 10 (as shown in the example) or multiple discrete plugs 10 in the glass assembly 15. The example shown has a bearing ring 14 at the top and bottom portion of the plug 10, and a stabilizer 12 which covers the middle edge of the plug 10. A sealing element 11 is arranged between the bearing ring 14 and the stabilizer 12 on both sides of the plug 10. While the stabilizer 12 in this example is larger than that of the other figures, it is simply large to accommodate the thicker plug 10. It would also be possible for the stabilizer 12 to be in multiple pieces. In the case of multiple plugs 10 in the glass assembly 15, each individual plug 10 could have its own stabilizer 12 and/or sealing element 11.

The degree of fluid tightness is largely determined by the number and placement of sealing elements 11. For example, there could be the same number of stabilizers 12 as plugs 10, to avoid twisting, and two sealing elements 11 for each plug 10. For another example, if there are multiple plugs, rather than have one or two sealing elements 11 and one stabilizer 12 per plug, it is possible that there is only a sealing element 11 in contact with the uppermost plug 10 (as refenced to uphole) and another sealing element 11 in contact with the downhole most plug 10. The bearing ring could be in contact with the edges of all of the plugs 10, or only in contact with less than all of the plugs 10. This can be accomplished using a single stabilizer 12 or several stabilizers 12.

The sealing area 13 in the case of multiple plugs 10 or multiple layers of material in the plug 10, is determined in the same way as for a single plug of a single layer (i.e. the regions of the plug 10 that are fluid tight as determined by the sealing element 11 and other possible contributors).

FIGS. 3A-3D disclose the operation of a plug tubular 100 in the first, second, and third positions. FIG. 3A disclose the first, starting position. In FIG. 3A the plug 10 is not moving. FIG. 3B disclose a position in-between the first position and the second position, where the shear ring 50 has sheared and the seat 20 and the plug 10 are moving toward the breaker object 30. FIG. 3C disclose the second position, where the plug 10 makes contact with the breaker object 30. FIG. 3D disclose the third position, where the plug 10 has disintegrated and movement has ceased.

Thus, a plug assembly 200 has at least three different positions, depending upon the status of the plug's integrity and its position. In the first position, the seat 20 is stationary with respect to the tubular body 130 and the plug is intact. After the pressure threshold requirements are met, the plug assembly 200 transitions from the first position to the second position. In the second position, the seat 20 has moved axially until the plug 10 is in contact with the breaker object 30. The third position is when the plug 10 is destroyed and fluid connection is reestablished through the tubular 100. Note that the tubular 100 is in the same position as the plug assembly 200 that it houses. The plug 10 is arranged in the glass assembly 15. The sealing area 13 (not shown) would be where each sealing element 11 makes contact with the housing 140 (not shown) and/or the seat 20 (not shown).

FIG. 4 discloses a plug assembly 200 which comprises a height adjuster 40 on one side of the plug 10 and a seat 20 on the other side of the plug 10. The purpose of the height adjuster 40 is to allow for the height of the housing 140 on one side of the plug 10 to be adjusted. In this way, the space can be made larger for installation of the glass assembly 15, the glass assembly 15 inserted into the plug assembly 200, and the space made smaller with the height adjuster 40 to hold the glass assembly 15 in place. This will allow for the plug to be held in place better and/or easier installation of the glass assembly 15. This in turn allows for wider tolerances of the glass assembly 15, i.e the parts said assembly is made up of can have a wider range of tolerances when manufactured, because small differences can be made up for by adjusting the height adjuster 40.

In the disclosed example, the height adjuster 40 comprises an adjustment seat 41 and a mechanical adjuster 42. By adjusting the mechanical adjuster 42 (e.g. a nut or spring), the distance of the height adjuster 40 from the plug 10 is changed. In this example, the adjustment of the mechanical adjuster 42 moves the adjustment seat 41.

An example of a glass assembly 15 is disclosed comprising a plug 10 (the example shown is the same as in FIGS. 1A, 1B, 2C, 2D, 3A-3D). It comprises a bearing ring 14 between the height adjuster 40 and the plug 10 and a second bearing ring 14 between the seat 20 and the plug. A stabilizer 12 is arranged between the outermost edge of the plug 10 and the housing 140. Sealing element 11 are arranged between each bearing ring 14 and the stabilizer 12. As in the previous examples shown, the sealing element 11 is in contact with angled surfaces. In this example the seat surface 21 is angled, and the height adjuster 40 in contact with the sealing element 11 is angled. In the example shown, a mechanical adjuster 42 is arranged over the adjustable seat.

In an example, the height adjuster 40 can have threads on the outside which match threads in the housing 140 or tubular body 130. By turning the height adjuster 40, the gap between the adjustment seat 41 and the plug 10 would be adjusted. The threads do not need to run along the entire body of the height adjuster 40. They can for example run only on the upper portion (towards uphole) of the height adjustor, while the lower portion (towards the plug) has no threads against the housing but rather a seal against the housing. In this way the height adjuster 40 is a single piece, there is no separate mechanical adjuster 42. This is a preferred example of the height adjuster 40, as only one component is needed.

Thus, the height adjuster 40 is not limited to the example shown in FIG. 4 with the sloped edges and a rounded edge. In another example thereof, if the plug 10 has a square outer edge and does not have bearing ring 14, then the height adjuster 40 will normally have a flat surface where the adjustment seat 41 makes contact with the plug 10. If there is a bearing ring 14, then the adjustment seat 41 will have a contact surface that keeps the bearing ring 14 in place on the plug 10. The mechanical adjuster 42 can be also be a ring with threads along the outside that match treads in the housing 140. As the ring is turned, it pressed down on the adjustment seat 41.

FIGS. 5A-5D disclose different examples of a plug 10 where the plug surface 60 is made of straight surfaces (lines in the case of the 2D cross sections). The plug surface 60 comprises a top surface 61, and an edge surface 66. The edge surface comprises a bottom surface, a top edge surface 63, a middle edge surface 64, and a bottom edge surface 65.

The top edge surface 63 and bottom edge surface 65 are in reference to the middle edge surface 64. The middle edge surface 64 will be the edge surface 66 that contains the widest portion of the plug 10. In FIG. 5A, the plug 10 the edge surface 66 only has a middle edge surface 64 and two other surfaces (top edge surface 63 and bottom edge surface 65). The example plug 10 shown in FIG. 5B is rectangular and thus the edge surface 66 is the middle edge surface 64 (i.e. no top edge surface 63 or bottom edge surface 65). The example plug 10 shown in FIG. 5C has a plug surface plug surface 60 with a middle edge surface 64 and a bottom edge surface 65 (i.e. no top edge surface 63).

However, in examples of the plug 10 in FIG. 5D-5E the middle edge surface 64 is curved. In the case of FIG. 5D, the middle edge surface 64 is arranged between a top edge surface 63 and a bottom edge surface 65. In the example of FIG. 5E, the edge surface 66 does not comprise a top edge surface 63 but does comprise a bottom edge surface 65 and a middle edge surface 64.

In the examples of FIG. 5B, FIG. 5C, and FIG. 5E, there is no top edge surface 63, in this case the top edge surface 63 is the top surface 61. In the event of a plug 10 with a middle edge surface 64 that has a top edge surface 63 but not a bottom edge surface 65, the bottom surface 62 could be considered the bottom edge surface 65. While the examples of FIGS. 5A, 5B and 5D are symmetrical between top and bottom of the plugs 10, where “top” and “bottom” refers to the figures, the examples of FIGS. 5C and 5E are not. Please note that although the examples of FIGS. 5C and 5E are drawn in this direction, the direction of such plugs 10 in the well could be upside down from what is shown in said figures. This would depend on the intended application of the glass or plug assembly. If for instance the plug 10 of FIG. 5D is to be used in a plug assembly intended to be opened by a pressure surge from below the plug assembly, it may be preferable to turn it upside down as compared to the orientation shown in the figure.

FIGS. 6A-8 disclose further examples of the plug assembly 200 and tubular 100. While these figures disclose an example of a sealing bearing ring 16, the elements can be interchanged with the earlier presented examples. For example, the sealing bearing ring 16 could be exchanged with the bearing ring 14 that was disclosed in the previous examples. Another example is the positions of the shear ring 50 and the breaker assembly 32 in FIGS. 6A-9 could be used in the examples disclosed previously (and vice versa). The stabilizer 12 is not an essential element these examples.

Note that in the examples there is only a sealing bearing ring 16 on the downhole side. This is not a requirement. It may be possible for the sealing bearing ring 16 to be on the uphole side only. It is also possible for there to be a sealing bearing ring 16 on both the uphole and downhole side. A portion of the sealing could be provided by the sealing bearing ring 16 or it could provide the entire seal of the glass assembly 15.

There may need to be rearrangement of the sealing between different components in the plug assembly 200 or housing 140 in order to operate in a desired manner. In the examples shown, there is no seal between the breaker assembly 32 and the housing 140 or between the height adjuster 40 and the breaker assembly 32. In this configuration, while it would be possible to use a sealing bearing ring 16 on the uphole side, it would provide little to no benefit. Because of this, in these configurations, a standard bearing ring 14 is used.

FIG. 6A discloses a side view of a longitudinal cross section of an example of a plug tubular 100 with a plug assembly 200 in the first position.

As in previous examples, the shear ring 50 is comprised of a shear ring lip 51 and shear ring body 52. The shear ring 50 is arranged such than when sufficient force is applied, the shear ring 50 shears at the interface between the shear ring lip 51 and shear ring body 52.

The plug assembly 200 is arranged in at housing 140 in the tubular body 130. In this example it comprises a glass assembly 15, a seat 20, a breaker assembly 32, and a shear ring 50. The glass assembly 15 comprises a plug 10, a sealing bearing ring 16 on the bottom side, a bearing ring 14 on the uphole side, and a stabilizer 12 around the middle of the plug 10. The plug 10 is supported by the seat 20. The seat 20 is supported by the shear ring lip 51. The breaker assembly 32 comprises a breaker object 30 which is arranged in a breaker holder 31. The breaker holder 31 rests upon the shear ring 50.

The stabilizer 12 is made of a non-elastomeric material. A common example of an elastomeric material is rubber. This material is used primarily for sealing elements 11. While the properties of rubber are well suited for sealing, they are entirely unsuitable for stabilizers in the plug assembly 200. That is because the temperatures and pressures that the tubular 100 (and by extension the plug assembly 200) experience when in operation cause the rubber to deform and render them unable to perform their needed function of stabilizing and centralizing the plug in place. One difference between the examples of FIGS. 6A-9 is that the sealing bearing ring 16 is responsible for (at least partially) maintaining the fluid seal between the uphole and downhole side of the plug 10. Such a type of bearing ring bearing ring 14 will be referred to as a sealing bearing ring 16. In these examples, the sealing bearing ring 16 is entirely responsible for maintaining this seal. As is the case with the stabilizer 12, the sealing bearing ring 16 (and the bearing ring 14 disclosed previously) should be made of a non-elastomeric material.

An elastomeric material is simply not suitable for a sealing bearing ring 16. The temperatures and pressures can cause it to deform. There are several possible negative consequences that can occur if using an elastomeric bearing ring 11. Most commonly is that the elastomeric material will be forced out from its place between the housing 140 and the plug 10. Other examples include the possibility that deformation will break the seal around the plug 10 allowing the fluid to flow, cause premature rupture of the plug 10, or cause the plug 10 to twist during operation. Examples of suitable non-elastomeric materials for the stabilizer 12 or the sealing bearing ring 16 include thermo plastics, PEEK, soft metals, and other materials that can hold their shape well enough under operating conditions and not be squeezed out of form such that there is not enough support of the plug 10 or metal to metal contact between the plug 10 and another element of the plug assembly 200 or tubular 100. It is possible to coat a suitable material with rubber in order to improve the sealing properties of the sealing bearing ring 16, however the rubber is no able to accomplish the task alone.

The breaker holder 31 is shown as resting upon the shear ring 50. However, this is not necessary. As seen in previous examples, the breaker assembly 32 is arranged to keep the breaker object 30 in position such that the plug 10 can make impact with the breaker object 30. This is usually because the breaker object 30 is stationary with respect to the housing 140. One way to accomplish this is to attach the breaker object 30 or breaker assembly 32 to the housing directly.

FIG. 6B discloses a closeup of the plug tubular 100 and plug assembly 200 example as disclosed in FIG. 6A in the first position. The glass assembly 15 comprises a plug 10 with a sealing bearing ring 16 on downhole side of the plug, a bearing ring 14 on the uphole side of the plug, and a stabilizer 12 around its middle surface.

FIGS. 6C-6F discloses the plug tubular 100 example disclosed in FIG. 6A as the plug assembly 200 moves from the first position to the second position. When the pressure on the plug 10 is high enough, the seat 20, which is supported by the shear ring lip 51 causes the shear ring lip 51 to separate from the shear ring body 52. The seat 20 is now unsupported and will move and make contact with the breaker object 30. A stabilizer 12 helps to stabilize and center the plug 10. A sealing bearing ring 16 one side and a bearing ring 14 on the other. The sealing bearing ring 16 provides the sealing of the plug assembly 200.

FIG. 6C discloses the state of the plug assembly 200 after the shear ring 50 has sheared, but before the plug 10 has made contact with the breaker object 30. FIG. 6D shows the second position where the plug 10 made contact with the breaker object 30. FIG. 6E shows the breaker object 30 continuing through the plug 10 after the initial contact shown in FIG. 6D. Finally, FIG. 6F shows the plug assembly 200 in the third position where the plug 10 has been destroyed and flow through the tubular 100 is restored.

The bearing ring 14 above on uphole side of the plug 10, does not remain in contact with the plug 10 when the plug assembly 200 moves from the first to the third position. This is due to the bearing ring 14 resting on a shoulder in the breaker assembly 32. Note that it is possible for both the bearing ring 14 and the sealing bearing ring 16 to move with the plug 10. It is an advantage if the sealing bearing ring 16 moves with the plug as this maintains the fluid seal around the plug during the transition from the first to the second position.

FIG. 7 discloses an example of a breaker assembly 32 in a plug assembly 200. In this example, the shear ring body 52 is part of the breaker assembly 32, rather than a separate element as in many of the previous presented examples. One advantage of this may be that it can result in less installation time for a single element than installing two elements.

FIGS. 8A and 8B disclose an example of a height adjuster 40 of the plug assembly 200 in the first and third positions. This is a further example of the disclose of FIG. 4 (with accompanying discussion). As discussed above, only the downhole sealing bearing ring 16 moves with the plug 10 when moving from the first position. The bearing ring 14 remains in place. The shoulder in the housing 140 that the bearing ring 14 rests against, helps to prevent the height adjuster 40, the adjustment seat 41, mechanical adjuster 42 from putting too much pressure on the plug 10. This shoulder is not necessary as it is possible for the height adjuster 40 itself to provide the needed pressure.

In this example, the mechanical adjuster 42 of the height adjuster 40 is a coil spring. In addition to some of the examples of mechanical adjusters 42 that were disclosed in the discussion of FIG. 4 , wave springs, tension wires, disc springs, or other suitable tension devices would work as the mechanical adjuster.

While the height adjuster 40 disclosed in the previous examples have the height adjuster 40 applying force to the plug 10 and in the direction of the seat, this is not a requirement. In some cases, the height adjuster 40 could be a part of the seat 20 and would direct force through the plug 10 in the direction of the housing 140.

It may also be possible to apply a radial force from the height adjuster 40 rather than an axial force. A radial force could be used to hold the plug 10 in place by pushing it from the sides. One possibility of this would be to have height adjuster 40 arranged between the bearing rings.

The size of the height adjuster 40 is adjustable and can be changed. The specific type of height adjuster 40 will determine the exact way by which the size is changed. In figures that were disclosed, the size adjustment is in the axial axis of the plug assembly 200 and tubular 100. However as discussed above, it may be desirable to have a change in size possible in the radial axis.

One example of how the size of the height adjuster 40 can be changed is with height adjusters 40 that comprise springs. The size will change as the spring is compressed or expanded. Another example of how the size of the height adjuster 40 can be changed is with height adjuster 40 that do not have a restorative property to them.

The height adjuster 40 will remain at a specific size until they are adjusted to another size. In both cases, the size of the height adjuster 40 is adjustable.

In the disclosed examples of a height adjuster 40 in this application, there are two broad types of height adjusters 40 that have been presented. The first kind are those that do not have any restorative property to them (non-restorative). For these, the size of the height adjuster 40 does not change size until it is adjusted. This kind of non-restorative height adjuster 40 devices have a first position where there is no pressure applied to the plug 10, and a second position where the height adjuster 40 is in contact with the plug 10 and applies pressure. The mechanical adjuster 42 will adjust the pressure applied by the adjustment seat 41 until the desired amount of pressure is applied.

Another disclosed type was a height adjuster 40 with a tension device or spring (usually as the mechanical adjuster 42). These are restorative types of height adjusters 40. In these, the initial position is when the glass assembly 15 makes contact with the height adjuster 40. The spring will compress, and the pressure applied by the height adjuster 40 on the glass assembly 15 will increase. In the second position, the glass assembly 15 is in place and the spring will have expanded, and the pressure on the glass assembly 15 due to the height adjuster 40 will decrease. Note that if the spring was biased in the opposite manner, then the pressure would first decrease and then increase in the second position.

In both restorative and non-restorative examples, the height adjuster's 40 height is determined by the mechanical adjuster 42. For the non-restorative, it is the distance of the mechanical adjuster 42 that moves to push the adjustment seat 41 against the glass assembly 15. For a restorative height adjuster 40, it is the size of the spring as it compresses and expands.

In both of these two examples of height adjuster 40 categories, the pressure applied by the height adjuster 40 on the glass assembly 15 between the first and second position are not the same. It may be possible to have a height adjuster in which the first and second position have the same pressures depending upon the exact mechanism by which the height adjuster 40 operates.

Another example of a height adjuster 40 is one with a fluid for a mechanical adjuster 42. For example, the adjustment seat 41 could be in fluid contact with a fluid. Increasing pressure of the fluid to the adjustment seat 41 would push the adjustment seat 41 to increase pressure. Reducing the amount of fluid pressure would decrease the pressure that adjustment seat 41 applies to the glass assembly 15.

In operation, normally the height adjuster 40 will be adjusted such that it applies enough force on the plug 10 so that the plug 10 remains in place during operation of the plug assembly 200 when being operated in a closed position. In some examples disclosed, the fixed position with respect to the housing will be temporary as the plug 10 does eventually move in the axial direction to be broken. In other examples, such as with explosives, it is possible for the plug 10 to remain in its original place when it is broken.

Another way in which a height adjuster 40 could operate would be to move the adjustment seat 41 into contact with the glass assembly 15 and then insert a physical stop such that the height adjuster 40 could not move enough for the glass assembly 15 to become too loose for the plug assembly 200 to perform its intended function.

As discussed previously, only the downhole sealing bearing ring 16 moves with the plug 10 when moving from the first position. The uphole bearing ring 14 remains in place. The shoulder in the housing 140 that the uphole bearing ring 14 rests against, helps to prevent the height adjuster 40, the adjustment seat 41, and/or mechanical adjuster 42 from putting too much pressure on the plug 10.

One reason for this is that it allows the height adjuster 40 to provide enough force to keep the plug 10 in place during operation, but not so much that it causes the plug 10 to break prematurely or otherwise cause the plug assembly 200 to not operate as intended.

This shoulder is not necessary as it is possible for the height adjuster 40 itself to provide the needed pressure without risking of putting too much pressure on the plug 10. Also note that the feature of the uphole bearing ring 14 remaining stationary is not essential.

Also note that the stabilizer 12 is arranged in a groove within the breaker assembly 32 so that it does not move. However, this is not required. It can be an advantage in some applications if the stabilizer 12 moves with the plug 10.

FIG. 9 discloses an 3D exploded view of an example of a plug assembly 200. The plug assembly 200 comprises a sealing bearing ring 16 on the downhole side of the plug 10 and a bearing ring 14 on the uphole side of the plug 10. Around the bottom edge surface 65 is arranged a stabilizer 12. In the example shown the stabilizer 12 has a slit in it; rendering it non-fluid tight. In the example disclosed the sealing bearing ring 16 has a hole through it on the edge. In this way, it is possible for the sealing bearing ring 16 to seal between the plug 10 and the housing 140 (not shown) without sealing on the edge portion which is often against a vertical surface. Lack of sealing on the parallel sides of the housing 140 can make it easier for the housing 140 to move from the first position to the second position.

Note that even though the examples of FIG. 8A and FIG. 8B does not have any sealing elements 11 (not shown) this configuration is possible. This would be similar to the examples present previously where there is a sealing element between the stabilizer 12 and the bearing ring 14.

The examples have been disclosed the stabilizer 12 as being arranged in a recess in the breaker assembly 32. The breaker object 30 can be mounted directly in the wall. It would be possible for the recess to be in the housing 140 or tubular body 130. The examples show that the stabilizer 12 remains in place as the plug assembly 200 during transition from the first position to the second position, this is not necessary. It could be allowed to move with the plug 10. This may be useful to help stabilize the plug 10 when changing position to further aid in keeping the plug 10 aligned correctly.

The meaning of the example of a stabilizer 12 that is not fluid tight is that the stabilizer 12 has no role in providing a fluid seal in the glass assembly 15 or the glass assembly when in the plug assembly (200). In other words, the stabilizer 12 alone would not provide enough sealing, or any at all, to prevent fluid from going around the plug 10. This role is filled by one or more sealing elements 11 and/or one or more sealing bearing rings 16.

Please note that “step of” is not to be interpreted as “step for”. By “comprised of”, “comprising”, “comprises” etc. we are referring to an open set and by “consisting of” we are referring to a closed set.

Modifications to the embodiments previously described are possible without departing from the scope of the invention as defined by the accompanying claims. Numerals included within parentheses in the accompanying claims are intended to assist understanding of the claims and should not be construed in any way to limit the subject matter claimed. Reference to the singular is also to be construed as relating to the plural unless expressly stated otherwise. Any reference numbers in the claims are provided as a courtesy and are not to be interpreted as limiting the claim in any way. 

It is hereby claimed:
 1. A plug assembly (200) comprising: a housing (140); glass assembly (15) comprising a plug (10); and a height adjuster (40) comprising a mechanical adjuster (42); wherein: the glass assembly (15) and the height adjuster (40) are arranged in the housing (140); the height adjuster (40) is arranged to apply pressure to the glass assembly (15); and the height of the mechanical adjuster (42) is adjustable.
 2. The plug assembly (200) according to claim 1, wherein the height adjuster (40) is restorative.
 3. The plug assembly (200) according to claim 1, wherein the height adjuster is non-restorative.
 4. The plug assembly (200) according to claim 1, wherein the height adjuster (40) further comprises an adjustment seat (41), and the adjustment seat (41) is in contact with the glass assembly (15).
 5. The plug assembly (200) according to claim 1, wherein the plug assembly (200) further comprises as seat, wherein the seat (20) supports the glass assembly (15) from one side and the height adjuster (40) supports the glass assembly (15) from the other side.
 6. The plug assembly (200) according to claim 1, wherein the mechanical adjuster (42) is arranged to change the pressure applied to the glass assembly (15).
 7. The plug assembly (200) according to claim 1, wherein the mechanical adjuster (42) is a spring.
 8. The plug assembly (200) according to claim 1, wherein the mechanical adjuster is threaded.
 9. The plug assembly (200) according to claim 1, wherein the glass assembly (15) further comprises a bearing ring (11) arranged between the plug (10) and the height adjuster (40).
 10. The plug assembly (200) according to claim 1, wherein the height adjuster (40) is configured with a first and second position; wherein: in the first position of the height adjuster (40), the height adjuster (40) applies a first pressure to the glass assembly (15); and in the second position of the height adjuster (40), the height adjuster (40) applies a second pressure to the glass assembly (15).
 11. The plug assembly (200) according to claim 10, wherein in the first position, the height adjuster (40) applies no pressure to the glass assembly (15).
 12. The plug assembly (200) according to claim 1, wherein the height adjuster (40) holds the glass assembly (15) in place, while the plug (10) is intact and stationary.
 13. The plug assembly (200) according to claim 1, further comprising a breaker object (30) wherein: in the first position, the plug (10) is intact and stationary; and in the second position the breaker object (30) has made contact with the plug (10).
 14. The plug assembly (200) according to the claim 13, further comprising a shear ring (50) which supports the seat, wherein: the breaker object (30) is not in contact with the plug (10) in the first position; and the shear ring (50) has sheared the shear ring (50) is arranged to shear when a pressure above a threshold pressure is applied to the glass assembly (15), releasing the plug and moving to the second position.
 15. The plug assembly (200) according to the claim 14, wherein the glass assembly (15) further comprises a first bearing ring (14) between the height adjuster (40) and the plug (10), wherein the first bearing (14) is not in contact with the plug (10) when in the plug assembly (200) is in the second position.
 16. The plug assembly (200) according to claim 1, wherein the glass assembly (15) further comprises a stabilizer (12) and wherein: the stabilizer is at least partially non-elastomeric; the plug (10) further comprises a middle edge surface (64) which contains the widest portion of the plug (10); and the stabilizer (12) is arranged around at least a portion of the middle edge surface (64).
 17. A method of installation of glass assembly (15) into a plug assembly (200), the plug assembly comprising: a seat (20); a glass assembly (15) comprising a plug (10); and a height adjuster (40) arranged with an adjustable height; wherein: the seat (20) is arranged to support the plug (10); a gap is arranged between the height adjuster (40) and the seat (20); and the method comprising the steps of: (a) adjusting the size of the gap to be larger than the thickness of the glass assembly (15) with the height adjuster (40); (b) inserting the glass assembly (15) into the gap; (c) resting the glass assembly (15) on the seat (20); and (d) adjusting the size of the gap to be smaller than in step (a) with the height adjuster (40).
 18. The method according to the claim 17, wherein in step (b), the glass assembly (15) is in contact with the height adjuster (40).
 19. The method according to claim 17, wherein in step (c), the glass assembly is not in contact with the height adjuster (40). 